The Obama administration took new steps Wednesday toward implementing the individual mandate in its signature healthcare law, downplaying the scope of the unpopular provision by stressing rules that allow exemptions from the requirement to purchase insurance.

The Internal Revenue Service and the Health and Human Services Department emphasized exceptions to the mandate, which were detailed in new regulations that also laid out the process by which the IRS will calculate penalties for going uninsured.

The mandate requires most taxpayers to either buy insurance or pay a fine to the IRS. It’s one of the most politically unpopular provisions of the healthcare law, and was at the core of last year’s historic Supreme Court case over the healthcare law.

HHS referred to the politically charged provision as a system of “shared responsibility” payments.

The mandate penalty “applies only to the limited group of taxpayers who choose to spend a substantial period of time without coverage despite having ready access to affordable coverage,” HHS said in a fact sheet on the new rules.

The same fact sheet also noted findings from the Congressional Budget Office that less than 2 percent of the American public will have to make a payment under the mandate.

In 2014, people who choose not to buy insurance and don’t quality for an exemption from the mandate will have to pay a fine of $95. The penalty increases to $695 by 2016, and then rises annually based on a pre-determined formula.

Although conservatives have railed against the mandate since Obama adopted it in 2009, some policy experts are concerned that it’s too weak to work — that it won’t be an effective incentive for young, healthy people to buy insurance.

Still, HHS and the IRS chose to focus on exceptions as they implemented the mandate Wednesday.

The Affordable Care Act includes exceptions for people with religious objections to traditional healthcare services, as well as a slew of income-related carve-outs.

“A principle in implementing the individual shared responsibility provision is that the shared responsibility payment should not apply to any taxpayer for whom coverage is unaffordable, who has other good cause for going without coverage, or who goes without coverage for only a short time,” HHS said.

People who do not make enough money to pay federal income taxes aren’t subject to the mandate, and neither are people for whom coverage would be unaffordable, as defined by the healthcare law. For employer-based coverage to meet the law’s definition of affordability, it can’t cost more than 9 percent of an employee’s salary.

Undocumented immigrants aren’t subject to the mandate, since they’re ineligible for government assistance to help buy healthcare coverage.

HHS also clarified in the new rules that short gaps in coverage won’t trigger the coverage requirement — meaning people who are temporarily unemployed won’t have to pay a fine for losing their health coverage between jobs.

Anyone who had insurance for one day of a month will count as having coverage for the whole month, HHS said.